Lice repellant composition

Abstract

It has been discovered that terpenoids, especially terpenoid-alcohols (terpene-ols) and terpenoid-esters, and some aldehydes and ketones of terpenes, in a concentration of between 0.01% and 50% by weight, most preferably between 0.01% and 10%, are very good lice repellents. The active agent can be combined with a pharmaceutically and/or cosmetically acceptable carrier for topical administration, such as an aqueous or alcohol solution, a gel, cream, or a powder, and administered with or without additives such as other insect repellents, agents increasing solubility or delaying release of active agents, antimicrobials, antioxidants and fragrances. Examples demonstrate efficacy in in vitro and in in vivo testing.

We claim: 
     
       1. A method to repel lice, comprising applying to a human or an animal susceptible to lice infestation an effective amount to repel but not kill lice of a terpenoid or a mixture of terpenoids in an acceptable carrier for topical application to a human or an animal, wherein the terpenoid is selected from the group consisting of a terpene-ol other than linalool, terpene ester, essential oil containing at least 40% terpene-ol or terpene-ester, cytral, nerol, ionone, dihydrocarvone, and pullegone, wherein the composition does not contain any non-terpenoid insecticides or repellants. 
     
     
       2. The method of claim 1, wherein the carrier comprises a terpenoid or mixture of terpenoids in a concentration of approximately between 0.01% and 10%. 
     
     
       3. The method of claim 1, wherein the terpenoid is selected from the group consisting of terpene-ols and terpene-esters, not including linalool. 
     
     
       4. The method of claim 1, wherein the carrier comprises an oil containing greater than 40% terpenoid by weight. 
     
     
       5. The method of claim 4, wherein the oil is a perfume. 
     
     
       6. The method of claim 1, wherein the terpenoid is an unsaturated terpene. 
     
     
       7. The method of claim 6, wherein the unsaturated terpenoid is selected from the group consisting of terpinene, pinene, limonene, myrcene, and carene. 
     
     
       8. The method of claim 3, wherein the terpene-ol is selected from the group consisting of perillyl alcohol, carveol, myrtenol, cis-verbenol, myrtanol, isopinocampheol, dihydrocarveol, isopulegol, terpineol, terpinen-4-ol, nerol, geraniol, menthol, β-citronellol, and dihydromyrcenol. 
     
     
       9. The method of claim 3, wherein the terpene-ester is selected from the group consisting of carvyl acetate, carvyl propionate, menthyl lactate, and iso bornyl acetate. 
     
     
       10. The method of claim 1, wherein the terpenoid contains an aldehyde functional group. 
     
     
       11. The method of claim 10, wherein the terpenoid aldehyde is selected from the group consisting of cytral and neral. 
     
     
       12. The method of claim 1, wherein the carrier is a material selected from the group consisting of an aqueous solution, an alcohol solution, a gel, a cream, a powder, spray, shampoo, conditioner, and hair styling mousse. 
     
     
       13. The method of claim 1, wherein the carrier further comprises a compound selected from the group consisting of antimicrobial preservatives, antioxidants, repellents for insects other than lice, fragrances, substances increasing binding of terpenes to hair, and substances delaying dissolution of the terpenes. 
     
     
       14. The method of claim 1, wherein the terpenoid is selected from the group consisting of essential oils containing at least 40% terpene-ol or terpene ester, further comprising a fragrance other than the terpene-ol or essential oil containing terpene-ol or terpene ester. 
     
     
       15. A method to repel lice, comprising applying to a human or an animal susceptible to lice infestation an effective amount to repel but not kill lice of a composition comprising linalool, essential oil containing at least 40% terpene-ol or terpene ester, and a terpene aldehyde in a topical carrier.